<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
<!-- <script src="https://cdn.jsdelivr.net/npm/vue@2.5.21/dist/vue.min.js"></script>-->
</head>
<body>

<div id="app">
    {{message}}
</div>

<!--也可以放在这里-->
<script src="https://cdn.jsdelivr.net/npm/vue@2.5.21/dist/vue.min.js"></script>
 <script>
     var vm=new Vue({
         el:"#app",
         data:{
             message:"hello vue!！！"
         }
     });
 </script>
</body>
</html>